Such devices provide the best results for a minimum area of solar sensor and a minimum mass of batteries. Such regulated buses at 50 V or indeed at 100 V are used for geostationary telecommunications satellites and are presently implemented for constellations of satellites such as SKYBRIDGE or indeed CELESTRI/TELEDESIC.
At present, there exist several known architectures for powering a bus from a solar energy generator and from an electrical energy storage unit comprising one or more batteries.
The first concept implements three operating domains, specifically shunt control of excess solar energy generated at a given instant (via a short circuit), charging the energy storage unit, and discharging the energy storage unit. The operating domains are controlled by a control loop which governs the transition between modes and which manages conflicts between operating modes (for example charging and discharging the battery(ies)). That concept requires both a battery charge regulator and a battery discharge regulator to be implemented.
A second concept implements two operating domains, specifically shunt control and discharge of the battery(ies). The charge regulator is not controlled by the control loop, and operation thereof is simplified, however it is no longer possible to manage conflicts.
In a third known concept, referred to as a "hybrid bus", the solar generators are subdivided into two groups, one of which is allocated to powering the bus and the other to charging the batteries. This makes it possible to omit the charge regulator, but operation is not optimized and it turns out to be sensitive to failures in the solar generators.